import java.util.HashSet;
import java.util.Set;

public class testSet {
    public static void main(String[] args) {
        Set set=new HashSet();
       Demo demo=new Demo(1);
       Demo demo1=new Demo(1);
        set.add(new Demo(1));
        set.add(new Demo(1));
        System.out.println(set.hashCode());
        System.out.println(demo.hashCode());
        System.out.println(demo1.hashCode());
    }
}
